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Europe · +420

Czech Republic phone number format

  • Country code +420
  • No trunk prefix

Reviewed by Sujan ThapaliyaLast updated

What does a Czech Republic phone number look like?

9 digits, always. Landlines are written +420 XXX XXX XXX and mobiles +420 [67]XX XXX XXX. In full international (E.164) format a Czech Republic mobile is written +420601234567: the country code +420, and no spaces or punctuation.
The anatomy of a Czech Republic phone number under ITU-T E.164: country calling code 420, then the national destination code, then the subscriber number, to a maximum of fifteen digits after the plus. Nationally a Czech Republic number is written +420 XXX XXX XXX; in E.164 the prefix and the spacing both come off.
National formatting is for people. E.164 is for databases, APIs, and caller ID — store Czech Republic numbers in the right-hand form.

Format rules

Country code
+420
National number length
9 digits, always
Trunk prefix
None
The local number is already the international number.
Landline pattern
+420 XXX XXX XXX
Mobile pattern
+420 [67]XX XXX XXX

Examples

Czech Republic phone number examples

These are format patterns showing digit grouping and prefix rules. They are examples of shape, not working numbers; do not use them to test a live call path.

TypeWritten domesticallyInternational (E.164)
Landline212 345 678+420212345678
Mobile[67]XX XXX XXX+420601234567

Validation

How to validate a Czech Republic number

Validating a phone number is three separate checks, and conflating them is the usual source of bugs:

  1. Format: does it match the shape for Czech Republic? 9 digits, always, after the country code .
  2. Allocation: is the prefix actually in use? A number can be the right length and still belong to an unallocated range.
  3. Reachability: is there a live subscriber? Only a carrier lookup (HLR or equivalent) answers that, and it is the only check that catches disconnected numbers.

For form validation, check format only and be permissive: accept spaces, dashes, brackets, and a leading 0 then normalise. Rejecting a real customer because they typed their own number the way they normally write it is a far more expensive error than storing one badly formatted row.

Store in E.164 (+420601234567) and format for display at render time. Storing the display format is how a database ends up with the same person recorded four different ways.

Format any number instantly

Paste a number into the free phone number formatter to convert it to E.164 and see whether it matches Czech Republic’s format rules. No sign-up.

Frequently asked questions

What does a Czech Republic phone number look like?
9 digits, always. A landline is written +420 XXX XXX XXX and a mobile +420 [67]XX XXX XXX. In full international format that becomes +420601234567.
How do I write a Czech Republic number in international format?
Start with +420, then append the rest with no spaces or punctuation. +420 212 345 678 becomes +420212345678.
How many digits is a Czech Republic phone number?
9 digits, always.
How do I tell a Czech Republic mobile from a landline?
By the prefix. Mobiles follow the pattern +420 [67]XX XXX XXX, while landlines follow +420 XXX XXX XXX.
Should I store phone numbers with the plus sign?
Yes. Store every number in E.164: leading +, country code, national number, no spaces or punctuation, up to 15 digits. It is the only format that is unambiguous internationally, and it is what makes deduplication work. Format for display, store canonical.

Sources

  1. ITU-T Recommendation E.164 — The international public telecommunication numbering plan — International Telecommunication UnionThe international number format, the 15-digit maximum, and how country codes and national numbers compose.
  2. ITU-T International Numbering Resources — International Telecommunication UnionThe assignment of country calling codes and the published national numbering plans they belong to.

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